ORLANDO, FL (UroToday.com) - Dr. Robert Uzzo argued for observation in many renal masses. Despite the fact that kidney cancer is a lethal disease, it is also heterogeneous. Despite the fact that kidney cancer is a lethal disease, it is also heterogeneous. He performed a meta-analysis to compare partial nephrectomy, cryoablation, radiofrequency ablation or surveillance. The data showed that the patients selected for surgery were typically younger. Follow-up in the literature is twice as long (33 months) compared to cryotherapy or RFA. Relative risk of local recurrence was 7-fold for cryotherapy and 18-fold for RFA. Despite this, very few of the tumors metastasized.

In his series one-third of small renal masses do not grow by 3 years. This is likely due to many being benign. Lesions <4cm have an 86% likelihood of being low-grade. Metastasis lesions are more common if the lesion is growing rapidly (0.74cm/year) compared to 0.29cm/year in those that did not metastasize. He felt that a strategy included initial observation and intervention for tumor growth.

A nomogram developed by the Cleveland Clinic helps to stratify risk of progression to metastatic disease. He presented an argument for 5-year competing risk of death in older patients. A 72 year old man with a 2cm lesion has a 2% risk of death from kidney cancer compared to a 20% risk of dying from other causes. He compared observation to the complications of ablative therapy or partial nephrectomy. Overall, Dr. Uzzo presented a compelling argument for observation in appropriate patients.

Presented by Robert Uzzo, MD, at the Annual Meeting of the American Urological Association (AUA) - May 17 - 22, 2008. Orange County Convention Center - Orlando, Florida, USA.